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Abstract:

In a vehicle wheel suspension, a first trailing arm is oriented in the
longitudinal direction of the vehicle and a second trailing arm in the
direction of an angle bisector between the longitudinal and transverse
directions. The ends of the trailing arms determine a substantially
horizontal instantaneous axis for the wheel carrier relative to the
spring jounce and rebound motions of the vehicle chassis. The wheel
carrier is slightly pivotable about a toe axis under the influence of
braking forces. A support arm securely connects to the wheel carrier and
extends over a defined distance substantially in parallel with and
supported on the second trailing arm. The support is softer in the
horizontal direction than in the vertical direction. A suitable design of
the second trailing arm and/or the support arm allows a slight pivot
motion of the wheel carrier about the toe axis.

Claims:

1. A vehicle wheel suspension of a semi-trailer type, the vehicle wheel
suspension comprising: a wheel carrier; a first trailing arm extending
from the wheel carrier in an orientation approximately in a longitudinal
direction of the vehicle; a second trailing arm extending from the wheel
carrier approximately in a direction of an angle bisector between the
longitudinal direction of the vehicle and a transverse direction of the
vehicle; wherein ends of said first and second trailing arms comprise
trailing arm bearings by which the trailing arms are supported on a
vehicle chassis, said ends determining a substantially horizontal
instantaneous axis for the wheel carrier relative to spring jounce and
rebound motions of the vehicle chassis; wherein the wheel carrier is
slightly pivotable about a toe axis in a toe-in direction under the
effect of braking forces or side forces when driving through a curve on
an outside wheel mounted on the wheel carrier due to an operative
configuration of at least one of the trailing arms and an operative
elastic configuration of at least one of the trailing arm bearings; a
support arm securely connected to the wheel carrier, the support arm
extending over a defined distance adjacent to and substantially in
parallel with the second trailing arm, the support arm being supported on
the second trailing arm in an area between a wheel carrier side end of
the second trailing arm and a vehicle chassis side end of the second
trailing arm via a support; wherein the support is operatively configured
to be softer in a substantially horizontal direction than in a
substantially vertical direction; and wherein an operative configuration
of at least one of the second trailing arm and the support arm allows a
slight pivot motion of the wheel carrier about the toe axis.

2. The vehicle wheel suspension according to claim 1, wherein the
operative configuration of the at least one of the second trailing arm
and the support arm comprises a configuration of at least one of the
second trailing arm and the support arm as a control blade arm, which is
rigid in a vertical direction and substantially in a transverse direction
of the vehicle, and further which is elastically deformable in a
horizontal plane in the longitudinal direction of the vehicle.

3. The vehicle wheel suspension according to claim 1, wherein the second
trailing arm is an independent component separable from the wheel
carrier; and wherein one end of the second trailing arm is coupled in an
articulated manner to the wheel carrier in order to represent a toe axis.

4. The vehicle wheel suspension according to claim 1, wherein the support
between the support arm and the second trailing arm is one of a pendulum
support and an elastic rubber bearing.

5. The vehicle wheel suspension according to claim 2, wherein the support
between the support arm and the second trailing arm is one of a pendulum
support and an elastic rubber bearing.

6. The vehicle wheel suspension according to claim 3, wherein the support
between the support arm and the second trailing arm is one of a pendulum
support and an elastic rubber bearing.

7. The vehicle wheel suspension according to claim 1, further comprising
a stop operatively configured to limit possible pivot motion of the wheel
carrier about the toe axis.

8. The vehicle wheel suspension according to claim 6, further comprising
a stop operatively configured to limit possible pivot motion of the wheel
carrier about the toe axis.

9. The vehicle wheel suspension according to claim 7, wherein the stop
defines the possible pivot motion of the support arm relative to the
second trailing arm.

10. The vehicle wheel suspension according to claim 8, wherein the stop
defines the possible pivot motion of the support arm relative to the
second trailing arm.

11. The vehicle wheel suspension according to claim 1, further
comprising: a web portion connected in one piece with the wheel carrier,
the web portion extending between the first trailing arm and the support
arm; and a support spring operatively configured to be supported on the
web portion, the support spring supporting proportionally the vehicle
chassis on the wheel.

12. The vehicle wheel suspension according to claim 10, further
comprising: a web portion connected in one piece with the wheel carrier,
the web portion extending between the first trailing arm and the support
arm; and a support spring operatively configured to be supported on the
web portion, the support spring supporting proportionally the vehicle
chassis on the wheel.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of PCT International Application
No. PCT/EP2010/001921, filed Mar. 26, 2010, which claims priority under
35 U.S.C. §119 from German Patent Application No. DE 10 1009 021
672.3, filed May 16, 2009, the entire disclosures of which are herein
expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] The invention relates to a vehicle wheel suspension of the
semi-trailer type with trailing arms, which extend from a wheel carrier.
A first trailing arm is oriented approximately in the longitudinal
direction of the vehicle, and a second trailing arm extends approximately
in the direction of an angle bisector between the longitudinal direction
of the vehicle and the transverse direction of the vehicle. The ends of
the trailing arms that are supported on the vehicle chassis by means of
trailing arm bearings determine a substantially horizontal instantaneous
axis for the wheel carrier relative to the spring jounce and rebound
motions of the vehicle chassis. Owing to the suitable design of at least
one of the trailing arms and the suitable elastic design of at least one
of the trailing arm bearings, the wheel carrier can be slightly pivoted
about a so-called toe axis, in particular in the toe-in direction, under
the influence of braking forces or lateral forces when driving through a
curve, on the wheel that is on the outside in a curve and is mounted on
the wheel carrier.

[0003] With respect to the prior art, reference is made, in particular, to
DE 32 42 930 C1 and, furthermore, to EP 0 052 153, even though the latter
document does not show a semi-trailer axle, but rather an especially
elastic construction of an elastic trailing arm bearing at various spring
rates in directions that are approximately perpendicular to each other.

[0004] The person skilled in the art knows that simple semi-trailer type
wheel suspensions, which are used preferably at the driven rear axles of
motor vehicles, have an undesired oversteer tendency in that the wheel
that is on the outside in a curve toes out subject to the action of
lateral forces. A number of remedial measures to counteract this problem
have already been proposed (cf., for example, DE 39 00 336 C2, DE 102 49
44 5A1, DE 32 42 930 C1). When braking or cornering, these strategies
allow the wheel that is on the outside in a curve to be pivoted in the
toe-in direction under the influence of lateral forces. Yet even those
prior art strategies that do not exhibit any notable disadvantages from
the viewpoint of driving dynamics have not gained acceptance. Hence, it
has not been possible to achieve adequate stability, subject to
reasonable engineering, with a wheel suspension according to DE 32 42 930
C1, which appears to have kinematic advantages and is deemed to be the
closest prior art.

[0005] Based on this prior art, there is needed a kinematically
advantageous wheel suspension that can also satisfy the additional
demands of being put into large scale production, in particular for
passenger vehicles.

[0006] This and other needs are met according to the invention by
providing a support arm that is securely connected to the wheel carrier
and extends over a defined distance next to the second trailing arm
substantially parallel to the same, and is supported on this second
trailing arm in the area between its wheel carrier sided end and the
vehicle chassis sided end by way of a support The support is much softer
in the substantially horizontal direction than in the substantially
vertical direction. A suitable design of the second trailing arm and/or
the support arm allows a slight pivot motion of the wheel carrier about
the toe axis. To this end, there are a plethora of options for designing
or developing the second trailing arm in such a way. One possibility of a
suitable design for the second trailing arm and/or the support arm
consists of configuring at least one of these two trailing arms in the
manner of a so-called control blade arm so as to be rigid in the vertical
direction and substantially in the transverse direction of the vehicle
and so as to be elastically deformable in the horizontal plane in the
longitudinal direction of the vehicle.

[0007] An alternative possibility that shall be explained in detail below
in the form of an embodiment consists of a second trailing arm being an
independent component that can, therefore, be separated from the wheel
carrier. One end of the second trailing arm or component is connected in
an articulated manner to the wheel carrier, in order to represent the toe
axis.

[0008] Both the support arm proposed herein and the second trailing arm
can be designed in a simple way so that they can permanently absorb the
forces that are to be transmitted and that predominantly involve the
lateral forces acting on the wheel. The same applies to the bearings or
joints, by which the second trailing arm is ultimately connected to the
vehicle chassis. Similarly, the wheel carrier with the first trailing arm
can be easily designed so that it satisfies all of the requirements
without having to pay particular attention to the desired pivot motion in
the toe-in direction when designing the wheel carrier, for example, with
respect to stability. In other words, the engineering object is achieved
by using, instead of the past conventional simple semi-trailer, a
semi-trailer that is formed from two components that can be slightly
pivoted in relation to each other about the toe axis essentially in the
horizontal plane. In this case the second trailing arm and the support
arm, which is also integrally connected, like the first trailing arm, to
the wheel carrier, extend preferably over a defined distance essentially
parallel next to each other. The latter guarantees in an advantageous way
optimal wheel guidance, especially under the influence of lateral forces.
At the same time the second trailing arm can also be connected in one
piece to the wheel carrier. However, this second trailing arm then has to
exhibit adequate flexibility in order to produce the desired pivotability
of the wheel carrier. As an alternative, the second tailing arm may be an
independent component that is mounted in a slightly pivotable manner on
the wheel carrier in the vicinity of the wheel.

[0009] Moreover, the trailing arm bearing of the first trailing arm is
constructed in a manner analogous to that of the prior art mentioned
above, that is, relatively rigid in a direction, which extends
essentially in the longitudinal direction of the vehicle, and relatively
soft in a direction that is perpendicular thereto, in order to allow a
toe change of the wheel under the influence of lateral forces.

[0010] The support between the support arm and the second trailing arm is
designed preferably in such a way that the wheel that is on the outside
in a curve is pivoted in the toe-in direction under the influence of
lateral forces and under the influence of braking forces in the
straightline travel of each wheel. This feature is achieved, on the one
hand, by a support, which is relatively soft in the substantially
horizontal direction and exhibits a preset elasticity that is different
in different directions. In contrast, this support is relatively hard or,
more specifically, non-elastic in the substantially vertical direction,
in order to be able to represent a precise wheel control. In any event in
a design of the second trailing arm as an independent component that is,
therefore, separable from the wheel carrier, this desired elastokinematic
behavior is achieved in that the support between the support arm and the
second trailing arm is disposed relative to the hinge point of the second
trailing arm on the wheel carrier. This is done in such a way that the
support arm and, thus, also the wheel carrier are pivoted in the
substantially horizontal direction under both the influence of lateral
forces and also under the influence of braking forces on the wheel,
mounted on the wheel carrier, or slightly tilted in such a way relative
to the second trailing arm that the wheel (the wheel that is on the
outside in a curve when cornering) moves in the toe-in direction. In this
context, this support between the support arm and the second trailing arm
can be configured in the form of a pendulum support or a rubber bearing
exhibiting an elasticity that is suitably different in different
directions.

[0011] Moreover, it is advisable in terms of a wheel control that is as
precise as possible under all boundary conditions, for the possible pivot
motion of the wheel carrier or, more specifically, the support arm
relative to the second trailing arm, to be defined by a limit stop.
Finally, an arrangement of the supporting spring that is provided for the
vehicle chassis and that is optimal in terms of both the force and also
the necessary design space is disclosed. It is self-evident that other
arrangements of the supporting spring are also possible. Moreover, the
latter also applies to the arrangement of a damper that is functionally
connected in parallel to the supporting spring. The embodiment that is
described below and that is used to explain the invention in detail shows
one possibility of this arrangement.

[0012] Other objects, advantages and novel features of the present
invention will become apparent from the following detailed description of
one or more preferred embodiments when considered in conjunction with the
accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a first isometric view from the outside, where the
direction of travel is indicated by the arrow F;

[0014] FIG. 2 is a second isometric view from the inside, that is, from
the center of the vehicle, and the direction of travel corresponds once
more to the arrow F;

[0015] FIG. 3 is a rear view of the wheel suspension from the rear;

[0016] FIG. 4 is a side view from the outside;

[0017] FIG. 5 is a top view from the top onto the wheel suspension;

[0018] FIG. 6 is a sectional view A-A from FIG. 5;

[0019] FIG. 7a and FIG. 7b show, once again, the section A-A and the
section B-B from FIG. 5 for purposes of elucidating the kinematic
relationships; and

[0020] FIG. 8a and FIG. 8b (comparable to FIGS. 7a, 7b) show an
alternative embodiment, in which the support of the support arm is
rotated clockwise relative to the second trailer by a defined amount.

DETAILED DESCRIPTION OF THE DRAWINGS

[0021] A left rear wheel suspension of a passenger vehicle is shown as an
exemplary embodiment of the invention in figures. In all of the figures,
identical components are marked with the same reference numerals.

[0022] In this context a wheel carrier, on which a wheel (not illustrated)
is mounted in a rotatable manner about its axis of rotation, bears the
reference numeral 1. A first trailing arm 2 is provided in one piece on
this wheel carrier 1. Extending from the wheel carrier 1, this first
trailing arm is oriented towards the front essentially in the
longitudinal direction of the vehicle (or more specifically the direction
of travel F). A second trailing arm 3 is connected in an articulated
manner to the wheel carrier 1 at a point P1 that is located on the wheel
carrier 1 relatively near the wheel. This second trailing arm 3 extends
from the wheel carrier 1 essentially in the direction of an angle
bisector between the longitudinal direction (F) of the vehicle and the
transverse direction (vertical thereto) of the vehicle.

[0023] A so-called support arm 4, which is connected in one piece to the
wheel carrier 1, and, thus, also extends from the wheel carrier 1,
extends substantially parallel to this second trailing arm 3 over a
portion thereof. Between this support arm 4 and the first trailing arm 2
a supporting spring 6 is supported on a so-called web portion 5, which is
also integrally connected, like the first trailing arm 2 and the support
arm 4, to the wheel carrier 1. As a result, the supporting spring 6
represents a component of this one piece "composite" comprising the wheel
carrier 1, the first trailing arm 2, the support arm 4 and the web
portion 5. Ultimately, this supporting spring supports proportionally the
vehicle chassis (not illustrated) on the wheel carried by the wheel
carrier 1.

[0024] A conventional damper for damping, by way of the supporting spring
6, the possible spring jounce and rebound motion of the vehicle chassis
relative to the wheel carrier 1 is marked with the reference numeral 7
and is mounted on the wheel carrier 1 at a suitable place and fastened
with its other end on the vehicle chassis.

[0025] The free end of the first trailing arm 2 has a receptacle for a
trailing arm bearing 2a (not illustrated in detail) preferably in the
form of a rubber bearing, by which this first bearing arm 2 is supported
directly or indirectly on the vehicle chassis. At each end of the second
trailing arm 3 there is a receptacle for a trailing arm bearing 3a or 3b
respectively (not illustrated), preferably in the form of a rubber
bearing, so that the first end of this second trailing arm 3 is hinged at
point P1 on the wheel carrier 1 by means of the trailing arm bearing 3b,
and its second end is supported directly or indirectly on the vehicle
chassis by means of the trailing arm bearing 3a. Furthermore, in the
region between the two ends of the second trailing arm, this second
trailing arm 3 has a support 8 for the support arm 4, extending from the
wheel carrier 1, or more specifically for its free end. In this case the
support 8 is formed by a rubber bearing 9 (cf. FIG. 6), which is pressed
into a receptacle 3c provided in the trailing arm 3 for this purpose.
This rubber bearing 9 and, thus, its support 8 is and/or are formed
significantly softer or more elastically in the substantially horizontal
direction than in the substantially vertical direction. Thus, the spring
constant C2 of this support 8 or the rubber bearing 9 that acts
essentially in the horizontal direction is significantly less than the
spring constant C1 of this support 8 or the rubber bearing 9 that acts
essentially in the vertical direction (cf. FIG. 6).

[0026] As in the case of wheel suspensions of the semi-trailer type, the
vehicle chassis sided trailing arm bearings 2a and 3a of the first
trailing arm 2 and the second trailing arm 3 generate an instantaneous
axis MA (cf. FIG. 5) that tilts (slightly) relative to the transverse
direction of the vehicle and about which the wheel carrier 1 is pivoted
relative to the vehicle chassis under tension or expansion of the
supporting spring 6 during the spring jounce or rebound of the vehicle
chassis. As in the case of the wheel suspensions according to the prior
art mentioned in the introduction, the first trailing arm 2 is provided
with a receptacle for the trailing arm bearing 2a in such a way and the
rubber bearing or rather trailing arm bearing 2a, which is provided in
this receptacle, exhibits different elasticities in mutually
perpendicular directions of the horizontal plane such that the wheel that
is mounted on the wheel carrier 1 moves in the toe-in direction during a
braking action. Analogous to this aforementioned prior art, the spring
constant CL1 (cf. FIG. 5) of the trailing arm bearing 2a that acts
essentially in the direction of the instantaneous axis MA is
significantly less than its spring constant CL2 that acts substantially
perpendicular to this instantaneous axis MA and, thus, predominantly in
the longitudinal direction of the vehicle, as a result of which there is
no automatic correlation between the rigidities of the trailing arm
bearing 2a and the instantaneous axis. Such a correlation was made herein
only for a rough indication of the orientation of these rigidities.

[0027] In addition, the support 8, or more specifically in the present
case the rubber bearing 9 between the support arm 4 and the second
trailing arm 3, is constructed in such a way and is disposed on the wheel
carrier 1 relative to the hinge point P1 of the second trailing arm 3 in
such a way that the support arm 4 is moved relative to the second
trailing arm 3 about the point P1 or more specifically about a so-called
toe axis AS (cf. FIG. 7b). This toe axis AS extends substantially or
approximately vertically through this point P1. The movement is in the
substantially horizontal direction or slightly tilted thereto, according
to arrow V (cf. FIG. 5), under both the influence of lateral forces (Fs
in FIG. 5) when driving through a curve and also under the influence of
braking forces on the wheel, which is mounted on the wheel carrier 1 and
whose center point is marked, inter alia, with MR in FIG. 5, so that the
wheel carrier 1 and, thus, the wheel is pivoted in the toe-in direction,
when it involves the wheel that is on the outside in a curve. In this
case the rubber bearing, provided in the receptacle 3b of the second
trailing arm 3, is constructed in a relatively rigid manner; as an
alternative, it is possible to provide, instead, a ball joint for
connecting the second trailing arm 3 in an articulated manner to the
wheel carrier 1 at point P1.

[0028] The possible movement path of the support arm 4 and, thus, the
possible pivot path of the wheel carrier 1 relative to the second
trailing arm 3 (to achieve the described pivoting of the wheel in the
toe-in direction) can be limited by a limit stop or more specifically by
a stop 10 in the present case (cf. FIG. 6). For this purpose after a
predefined length of travel the support arm 4 comes to rest laterally
against the second trailing arm 3.

[0029] The corresponding correlations are explained briefly once more by
use of FIGS. 7a and 7b. In particular, however, FIGS. 7a, 7b are compared
with FIGS. 8a, 8b for the purpose of explaining below an additional
"parameter," by which the present wheel suspension can be designed in
order to satisfy the respective requirements in terms of its
elastokinematic properties. In this case, this additional parameter is
not available in the wheel suspensions that are cited as the prior art.
Thus, this additional "parameter" constitutes an additional advantage of
the inventive wheel suspension over the known prior art and is formed by
the installation position or more specifically the tilt of the rubber
bearing 9 or rather by the configuration of the support 8 that is active
at a point P2 when viewed from a kinematic perspective.

[0030] A perpendicular to the road projection of the wheel center point MR
on the road E yields the road contact point R of the wheel. According to
FIGS. 6 and 7a, the rubber bearing 9 is disposed in the support 8, by
which the support arm 4 is supported on the second trailing arm 3 in such
a way that the softer support is exactly in the horizontal direction, and
the opposing significantly harder support is active along the axis A2
exactly in the vertical direction. Then the intersection point of the
axis A1, extending parallel to the axis A2 and through the point P1 in
the present embodiment, yields with the road the so-called lateral force
neutral point N. If the lateral force, acting on the wheel, were to
engage at this lateral force neutral point N, then the wheel would not
undergo a toe change under the influence of this lateral force. However,
for the investigations of the elastokinematic behavior, the lateral
forces engage at the road contact point R of the wheel. In the embodiment
according to FIG. 7b, the lateral force neutral point N is now behind the
road contact point R of the wheel by an elastokinematic negative caster
trail S1, when viewed in the direction of travel F. The result of the
lateral forces engaging at the road contact point R of the wheel is a
motion or more specifically a slight pivoting of the wheel that is on the
outside of a curve about the so-called toe axis AS in the toe-in
direction, so that this toe axis AS extends in essence vertically through
the lateral force neutral point. In the present figure, the toe axis AS
coincides with the axis A1, but it involves a special case, because it is
well-known that the course of the toe axis AS is also a function of the
configuration of the trailing arm bearing 2a. In this context it is
well-known that the camber stiffness is also a factor, but it is not
necessary to delve into the details thereof in the present embodiment.
Rather, the aforementioned additional "parameter" in the form of the
orientation of the axis A2 by suitably designing the support 8 shall be
discussed below.

[0031] If the rubber bearing 9, by which the support arm 4 is supported on
the second trailing arm 3 in the support 8, is arranged, according to the
modification according to FIG. 8a, so that the axis A2, defining the
substantially harder support, tilts relative to the vertical line and is
rotated clockwise by a defined amount with respect to the embodiment in
the drawing according to FIG. 7a, then the lateral force neutral point N
is located or more specifically "migrates," according to FIG. 8b,
(further) towards the front, when viewed in the direction of travel F,
because the axes A1 and A2 behave the same with respect to their tilt. In
the variant according to FIGS. 8a and 8b, the lateral force neutral point
N is located in front of the road contact point R of the wheel by the
elastokinematic positive caster trail S2, as a result of which the wheel
that is on the outside in a curve moves in the toe-out direction. It is
self-evident that it is also possible to have a neutral layout, where the
lateral force neutral point N coincides with the road contact point R of
the wheel. Therefore, when the rubber bearing 9 or more specifically the
support 8 is rotated in the clockwise direction U, according to FIG. 8a,
starting from the position according to FIG. 7a, the result is that the
lateral force neutral point N tends to move forward, so that, as the
angle of rotation increases, the toe of the wheel changes increasingly
less under the lateral forces until the lateral force neutral point N and
the road contact point R of the wheel coincide. Thereafter as the rubber
bearing 9 is further rotated according to the direction of the arrow U,
the wheel that is on the outside in a curve moves more and more in the
toe-out direction under the influence of the lateral forces. At the same
time, rotating the rubber bearing 9 in the direction of the arrow U
during a braking action and during a spring jounce, results in an
intensified tendency to steer the wheel in the toe-in direction. The
reverse behavior results from rotating the rubber bearing 9 counter to
the direction of the arrow U in FIG. 8a. Since the lateral force neutral
point is also fixed by the position of the point P1 on the wheel carrier
1, at which the second trailing arm 3 is mounted in an articulated
manner, it is self-evident that the behavior of the wheel under the
influence of the lateral forces can also be defined by suitably fixing
the position of the point P1. Furthermore, it must also be pointed out
that the axes A1 and A2 are not, or rather do not have to be, parallel in
the geometric sense, but rather it is important that their behavior tends
to be the same when the axis A2 is rotated in or counter to the direction
of the arrow U.

[0032] In contrast to the conventional semi-trailer axles, the toe and
camber of the wheel can be adjusted in a relatively simple way in the
inventive wheel suspension of the vehicle. To this end, the support 8 can
have a commensurate adjustment possibility, so that after opening this
adjustment possibility the support arm 4 can be moved slightly in
relation to the second trailing arm 3. When closing this adjustment
possibility, which can be configured, for example, in the well-known way
in the form of a bolt, which can be moved transversely to the drill hole
axis in a large drill hole, the toe and camber can then be defined. When
in the course of such an adjustment, the wheel carrier 1 is tilted about
the so-called adjustment axis ST (cf. FIG. 5) that is described by the
trailing arm bearings 2a and 3a, in that when the end of the support arm
4 that faces away from the wheel carrier 1 is moved essentially in the
vertical direction, the wheel camber is set. Thereafter the wheel toe is
adjusted by suitably moving the end of the support arm 4 essentially in
the horizontal direction. At the same time the trailing arm bearing 2a
has to be released, a state that can be achieved in principle in the
conventional way by loosening the associated bearing block (not
illustrated).

[0033] The foregoing disclosure has been set forth merely to illustrate
the invention and is not intended to be limiting. Since modifications of
the disclosed embodiments incorporating the spirit and substance of the
invention may occur to persons skilled in the art, the invention should
be construed to include everything within the scope of the appended
claims and equivalents thereof.